Bacterial ghost: A novel strategy for medicinal applications

Abstract

Bacterial ghost (BG) is an empty cell envelope of bacteria devoid of chromosomal and plasmid DNA and cytoplasmic content. However, it maintains the cellular morphology with native surface characteristics and bio adhesive properties. The widely used method to prepare BG is the protein E-mediated lysis method, which forms transmembrane tunnels through the inner and outer membranes of bacteria. There are also chemical and mechanical methods that lead to the formation of bacterial ghosts without damaging the necessary components and structure of bacteria. Alongside using NaOH, SDS, H2O2, tween 80, β-propiolactone, and 60% ethanol, hydrostatic pressure is also used to expel the cytoplasmic content resulting in pure envelop ghost. Recently developed holin-mediated inactivation, lysozyme, and protein kinase K are also used to kill bacteria, leaving them as BG. It is used in vaccines, immunotherapy of cancer, and a widely accepted delivery system of drugs, antigens, and other active components. The other efficient use of bacterial ghosts is to stimulate humoral and cell-mediated immunity through antigen-presenting cells. Taken together, BG represents a novel and emerging method for developing potential disease prevention and public health.